1. Truck roll-over crash prevention program.
Vehicle Management and Safety
March 2010
Hi everyone, I am here to introduce you to the Truck rollover crash prevention program.
We have seen a problem here with roll over crashes and the actions were not producing significant results. The number of crashes was not reducing and being hidden because of the stigma of having a roll over. So we had to find a new solution and developed this program.
What is the program? It really is just a way to present information so that all people can understand it, remember it when necessary, and it will probably save quite a few lives given our results so far. It consists of this presentation, some quite simple models, a framework to develop a self regulating code of behaviour. There are no rules to do it, no enforcement penalties if you don’t do it, just a simple way to make sure you come home to the family.
The idea has been used in one type of the trucking industry and has had incredible success. We have developed the concepts further and as we get more on board, more information is brought to our attention which helps in fine tuning the program. Of the test case, 15 trucks rolled in a six month period, and in the following six months, no roll over crashes have occurred. It is fundamentally about making people aware.

2. Heavy vehicle rollover prevention program
Aim to -
Create awareness to all stakeholders
Preserve driver
Reduce resultant trauma
Improve productivity
Reduce impact on environment
Reduce impact on community
Truck washer to bean counters, road designers, road builders, community,
Drivers cost money to replace, they are far too valuable to not look after. Use integrated seat belts, no loose cabin material, etc
$70,000 before even fixing the truck or driver

3. Load restraint test
This is a test of load restraints, not a test for a roll over. Lets watch the first run.
Now, when did the driver know he was in trouble?
[step to 90]
did he know before this? Then why aren’t his brake lights on?
He did not know until the trailer had dropped 90 degrees.
Now see how the cabin is flipped rapidly. The trailer has wound up like a spring and then released.

4. Analysis of load restraint test
While some would argue that this is recoverable, it is not, the weight is over the outside of the wheel and the momentum is pushing further. This is already too late.
Driver does NOT know the trailer is going
Already past the point of no return

5. Analysis of load restraint test
This is when the driver actually knows, and it is because the cabin is moving.
Driver now knows, brake lights on
1 sec elapsed time, rims being scrubbed

6. Analysis of load restraint test
Driver now feels it, catastrophic failure
2 sec elapsed time, cabin whipped over

7. Factors that influence roll-overs.
Speed
Gravity
Speed
Changing direction
Acceleration.
Driver experience.
Sloshing.
Load movement.
Type of load.
Restraints
Friction
Stiction
Centre of Gravity
Driver alertness
Sun
Wind
Brake condition
Couplings
Number of trailers
Roundabout size
R-A-Bout Camber
Lack of time intersection
Intersection size
Tight Corners
Wrong Camber
Road condition
On ramps
Off ramps
Load location
Load viscosity
Load packing
Low tare weights
Gross weight
Load heights
Bed heights
Trailer format
Camber change in turn
Road litter
Engine failure
Missed gear
Inappropriate selection
Lane change downhill
Suspension condition
Tyre condition
Tyre pressure
New tyres
Axle alignment
Suspension type
Time pressure
Other road users
Mobile phones
Road knowledge
Centrifugal Force
Gravity
Friction
Suspension
There is a lot of factors but we will only be able to consider these in the time we have
Centre of Gravity (COG)
Centrifugal Force

8. 20 T The forces centrifugal Centre of gravity
suspension
Centre of gravity
[Do the model of the tilt tray.]
Truck rollover demo, where does it roll? 50-60
Trailer with logs, before tip ask the question “so, where do you think it will roll?”
[Tip, emphasise the smallness of 15 degrees and this is still static!]
gravity
friction

9. Centre of gravity (COG)
Introduce wooden triangles
Discuss deck variations, drop deck versus standard.

10. Compared to a car
Extremely difficult to roll a car without a tripping effect. Tyres tend to slide first, much lower centre of gravity, and roll centre. Compared to a normally loaded truck, not pushing limits, the height is 1.5 metres above the car COG.
Refer to triangles again.

11. Do you know your load?
To know your centre of gravity you need to know your load well.
You may think that you know the weight but is it restrained or does it move inside, is it packed all on one side, heavy on one side and light on the other. Light on the bottom and heavy on top.

12. Load restraint issues
Load restraint means different things to different freight tasks, clearly, moving square boxes is what most people think of. Liquids require restraint too. And what about odd shapes, things like this conveyor belt, 19 tonnes, 3.6m in diameter, being transported to Brisbane and the numbers are increasing. Imagine that rolling forward as the truck slows down to negotiate a bend, no question of if it will roll, just when.

13. Centre of Gravity- it is that simple
It is that simple to find your centre and make sure that it will not overbalance.
[case study of swifts creek]
Model demonstration- sand vs Chip bark.
Verbal of load type change from quarry to chips.
Triangles for centre of gravity

14. Speed - Centrifugal force
If a vehicle is forced to take evasive action, these forces are further multiplied.
                                                                        
What to do:
Now we add the first dynamic force to the problem. Centrifugal force is due to two basic forces, speed and rate of change in direction. The tighter the turn the greater the force, the higher the speed the greater the force. BUT it does not just increase in a linear fashion, like 10% increase in speed causes 10% increase in force.
It increases by squaring so that 10% increase in speed causes 100% increase in force! Double the speed is four times the force!
Rearward amplification is a typical problem when you need to counter steer or swerve around a problem. That is a whipping effect when a small change in steering is amplified by the trailer.
If you double your speed, the overturning force will be four times higher.
As the speed increases the trailer tracks wider and forces increase on rear axle. This means that a slight increase in speed can be critical.

15. This is a demonstration of centrifugal force acting on a truck as it turns. Both speed and change in direction create this force, but you can clearly see, that it is only a marginal increase in speed and angle compared to the truck that negotiates safely.
[run the video twice, second time point out the minor correction point which followed the pick up, then, show where the truck corrected the second time which was a 30cm movement, look at the white line width for a guide]

16. Dynamic forces, now add dynamic load
Milk tanker
2 sec slosh cycle
Dynamically moving centre of gravity
We are now adding a further dynamic force, which further reduces the safety margin. The load constantly changes the centre of gravity because it sloshes about. The stability moves from side to side.
[ drop out of PowerPoint and run the Animation stand alone]
[Prove with the model, Perspex tube and two second slosh. The slosh timing takes practice but it should only take one or two quick movements of the tilt table up to degrees and drop again, then the next lift, time the roll of the rod as you lift the table to 20 degrees and stop, the truck will roll dramatically]

17. Known dynamic load - Concrete truck.
As the truck enters the roundabout, it is under brakes and slowing down, this pushes load towards the front, to the highest camber. The truck is usually slow or nearly stopped at this point, being ready to give way if necessary.

18. Known dynamic load - Concrete truck.
As it turns left, usually a slight left turn not a sharp turn, and then begins the slow right where the road is cambered in the trucks favour. The truck begins to accelerate, moving some material back towards the rear wheels.

19. Known dynamic load - Concrete truck.
The truck gains speed, camber is even and stabilizes the load, at this point the centrifugal force is almost zero. The force is changing from left to right.

20. Known dynamic load - Concrete truck.
The truck is now in the slow right movement where the road is cambered in the trucks favour even though the force is pushing it away from the centre of the roundabout, and the camber is rolling away from the centre, the weight of the truck material is pushing it back to the centre.
The second thing in the trucks favour is that the agitator requires force to rotate it, this force is equal and opposite to the drum rotation. The drum rotates anitclockwise, therefore the truck wants to rotate clockwise, pushing the truck towards the centrifugal force that is trying to push it out. This is one of the safest conditions that agitators experience.

21. Known dynamic load - Concrete truck.
The truck has now lined up the exit and will either maintain speed or drop slightly to turn left. Deccelaration moves material to front right of the drum. The truck begins the turn which changes the direction of the centrifugal force. There will be some camber change as it begins the turn.

22. Known dynamic load - Concrete truck.
The truck is at speed, a small camber change (may change and then return) which causes a suspension movement, there is a rapid change in the direction of the centrifugal force, material has been moved to the front right by the change and normal motion of the agitator drum…. And over it goes!

23. Roundabout example
High risk trucks must use this path, no where else to go. This is a typical work of art, but not very practical for truck movement, the path is down hill, sloping away from the centre, and the beautification program has added more risk with the raised pavement in the centre. That six inch rise will drop 5 degrees of rollover headroom on a milk tanker. They only have 15 static! Add the down hill slope and increased angle, plus loss of road space from the addition of the raised pavement, you have a very high risk site. If you think you can take it at 30kmph, better to go 15kmph instead.

24. Locations 1
This is an example of centrifugal force at speed, not speeding, he is not going faster than the cars, just going to fast for his load and road conditions. The term is ‘inappropriate speed’ . It is clear that the rear trailer bogie is off the ground even before you can see it. By the time he is in the centre of the picture, the truck is beyond saving and a crash is inevitable.
The load appears to be a large number of small boxes, and is loaded very high. Recall the centre of gravity issue.

25. Locations 2
Same again, but this time the truck is in the outside lane. The rear trailer bogie is off the ground well before rounding the bend, and has lost it by the centre of the picture. As always, the rear trailer always goes first.
When you get to these type of locations, take extra care. The problem is pretty much solved if every truck slows down 5 more taking extra care on these high risk locations.

26. Locations – you can roll in a straight line too!
Now that you have all the dynamics forces in mind, and you think you have it under control, along comes the environment. The load you carry is affected by the environment, here we have a light load going over.
Any ideas on what he could have or should have done?
Check the weather, know your load, go a different way, if you cant, then go tomorrow! This is not a bad one, but it could be a fatal if it fell on a car beside it.

27. Straight line roll – identical trucks
Ok, now we have no obvious environment issues, why did the first truck roll and not the second. Identical loads, good restraints, straight road, appropriate speed.
They were not quite identical, one is a cab over and the other long bonnet. Some prime movers are just better for some types of work. But in this case, it was a number of very small things which eventually add up to the crash. The first truck apparently crossed a rail crossing a short distance back and then developed a wobble which took only a few back and forth, then tipped over. Given the type of load and the possibility it may be slightly green or still wet, then the load is quite high and heavy. The centre of gravity in this case would be extremely high. If all conditions were ok then the truck may not tip over, but in this case, a disturbance to the suspension, the high centre of gravity, heavy load (reduces the rebound and travel of the suspension) will cause it to roll over.

28. All this leads to the ‘1k’ factor
Forces….summary
Fixed, constant types - gravity
Dynamic truck forces – centrifugal, speed, COG
Dynamic load forces, compounding on the truck
Unknowns … environment, other road users,
So, as little as 1 kph extra will make you roll over
If you are aware, and you add more than the 1kph space, that is give yourself decent headroom to allow for unknowns, you will get home without a roll over.
Summary of the forces
We have fixed forces such as gravity and friction, which will always be there.
There are dynamic forces such as centrifugal force, which is dependant on rate of change of direction and speed, and add COG
Then the dynamic dynamic forces which are affected by the dynamic forces above but react differently and independently, such as milk slosh, or one sided concrete rise with agitator rotation force.
When …..

29. Strategies Create a way that the industry can help themselves
Educate and inform the problem areas
Help the industry educate and inform associated industries
Review the freight task from a different perspective
Collect more focused data
Workshop the recommendations
Preserve the driver
We needed to find a way to make the industry help themselves, if they owned it, they would support it. The code of behaviour does this.
We had to educate (enlighten) any problem area, like the logging industry.
We need to provide tools for the industry to educate others such as road designers, fork lift operators, saw mills.
Review the freight task differently, can we take another route, can we load differently….
Collect data that leads up to the crashes, not just the last thing that happened, straw that broke the camels back.
Workshop the research recommendations, get programs planned for the future,
Last but not least, do what ever it takes to preserve the driver if he does have a crash. No eskys in the front, make sure he can wear a seatbelt.

30. Route management
Discovered other ways to reduce the risk. This is one of the milk transport maps from Austria. The routes are selected based on load and distribution. The tankers are loaded in cells, front and back on the trailer, and central to back on the prime mover. Not sure why but it seems logical on the trailer to load on and it was tested as the safest configuration. This was proven to reduce the number of roll over crashes.

31. Development of a self regulating code of behaviour
USE OF ENGINE BRAKES IN TOWNS
DROPPING OF DUST
LOAD SECURITY
USE OF UHF CB RADIO ON COMMON CHANNEL
ALLOWING TRAFFIC TO PASS
MASS LIMITS
TRAVELLING ON CORRECT SIDE OF ROAD
ROAD WORKS
TRAVELLING THROUGH TOWNS AND SCHOOL CROSSINGS
TIMES OF TRAVEL
LOAD HEIGHT
DRIVER INEXPERIENCE
FATIGUE MANAGEMENT
When developing a self regulating code of behaviour, consider topics like this. Look outside the ‘drive down the road’ and see what else you can do to gain support. Having people on side is much better in the long run, you will be surprised by how attitudes will change if you involve everyone.

32. Example of particular issue
ALLOWING TRAFFIC TO PASS
Issue
On narrow hilly and winding roads loaded log trucks generally travel slower than other vehicles. It is well known that many drivers get impatient when travelling behind a slower truck.
Action
We will as much as practicable (when safe and appropriate) slow down and pull to side of road to allow traffic to pass. When travelling behind another truck we will take into account the passing opportunities for other vehicles and not travel too close.
A typical example of how it can be written up. It was noticed on some of the trials, the cost to pull over added only a few minutes to the trip but got a number of calls from the public about how good the drivers were.

33. Preserve the driver
Top right, crashed at close to 100 kph, had some cuts and scratches. Yes, that is the front axle ripped out of the truck and sitting on the road, bottom right of the picture. Had a seat similar to that on the left and no loose material in cabin.
Bottom right, crashed at less than 50 kph, found on the footpath, went through the windscreen, no seatbelt, in serious condition. Passenger had to be cut from the cabin.

34. Cumulative factors case study
Who- Experienced driver who had driven this road many times before
What-A six axle semi fully loaded with packs of timber
When- three hours into eastbound trip, late afternoon
Where- Country road, right hand bend with 85kmh advisory sign
How- Rolled to the left side spilling its load of timber for 50m
This is a case study of a roll-over that occurred last year and the findings of an investigation by Vicroads and the operator.
We used a Who, What, Where, When, When, How, Why approach.

35. Load restraint issue, caused a rollover
Why
Driver had not carted this load before
High COG load (2 more packs than normal)
Load restraint and movement
Suspension tilt
New tyres
Truck had minor change of direction
Fatigue
Negotiated corner at approximately 85kmh as usual
Corner had developed bumps just prior to apex
Demo load restraint with wood pack.
Driver was experienced but had not carried this load before.
The load had a higher COG than he was used to.
The load although well restrained to meet the load restraint guide but was able to move at the top due to the 90deg strap angle.
Suspension tilt was magnified due to this change in COG.
Drivers had reported that the new drive tyres that were being used made to truck prone to wandering for the 1st 500km.
The truck had a minor change of direction to the left, (maybe due to deep tread new tyres, load movement or fatigue, the driver had to counter steer.
He negotiated the corner as usual, but the 85kmh corner characteristics had changed since the bumps appeared.
When we add all of these minor issues together, we had a roll-over…Take any away and it may not have occurred.

36. Corrective actions
Trucks fitted with new tyres have a yellow sticker indicating that care should be taken for first 5000km
Induction and mentoring program for drivers
All company personnel have attended a rollover awareness course
Drivers retrained on load restraint and re-tensioning of straps
Loading and restraint methods are being reviewed by all parties in the transport chain
The operator immediately set about putting actions in place to address the issues that were found,
Some of these were-

37. Logging industry actions
Development of a Code of Behaviour
Induction and mentoring program
Roll-over awareness sessions for all parties in the chain
Safety alerts for higher risk roads (Traffic management)
Voluntary load height limits on higher risk roads
Changes in loading and unloading practices
Change vehicle design, low bed heights and drop decks
Cutting wood specifically to length for each truck
Use most appropriate vehicle
Use of EBS roll-over stability braking systems

38. Code of behaviour actions
Concrete industry example-
Extensive education, mentoring and induction process.
Gain experience as a passenger, co driver, then low risk
Operator has identified more risky sections of roads
Safety alerts on risks issued to drivers
Turn drum off for higher risk loads on more risky sections of roads
Clean drums reduce weight
Truck characteristics individually assessed
use extra stiff suspensions for more hazardous roads
All drivers undergo an extensive education, mentoring and induction process.
Drivers gain experience as a passenger, then as a co driver and initially only drive one up with smaller and wetter loads on better roads.
The operator has identified roads in his area that are hazardous to concrete trucks, ie sections of roads or corners that have negative camber to the right side. A safety alert is issued alerting drivers to this risk.
Procedures are in place for higher risk loads such as kerb mix, to turn drum rotation off on hazardous sections of roads.
Drums are kept clean to reduce extra weight.
Each truck in the fleet has been individually assessed for its characteristics.
Trucks with extra stiff suspensions are preferred for use on hazardous roads.

39. Everyone will thank you for your effort
What can you do?
Be aware of the limits, not just your job
Back off more from the limits, not just speed
Be aware of the community impact
Keep the information flowing
Develop a code of behaviour, and OWN it!
Educate others, this is not a driver problem alone
If unsure, ask for help
This is an industry driven incentive, we are just helping you do it. You need to help each other do it.
Everyone will thank you for your effort

40. Where next Technology – RPS, EBS, Improvements in vehicle design
Improve this
Other research
Licence endorsements
Insurance cost reduction
National consistency